Guides to fix internal server error in WordPress

Solving WordPress issues is one of the problems both newbie and professional WordPress developers are facing nowadays.

NOTE: Before trying to fix any WordPress error, make sure that you have a complete WordPress backup(By using UpdraftPlus).
Let's begin from here.....

Internal server error in WordPress can be solved by:

• Checking for Corrupt .htaccess File
• Increasing the PHP Memory Limit
• Deactivate all Plugins
• Re-uploading Core Files

Firstly, What Causes Internal Server Error in WordPress?
This is the most confusing WordPress error that a  WP user may come across is “Internal Server Error”, or sometimes called “500 Internal Server Error”.

It appears when there is something wrong, whereby the server is unable to identify where the problem is. Since the error message does not indicate where you should look for the error, it is better much you to figure this out.

Internal server error is not specific to WordPress. It can happen with any website running on a web server. Due to the generic nature of this error, unfortunately it won't tell the developer anything.

Internal server error in WordPress is often caused by plugin or theme functions. Other possible causes of internal server error in WordPress that we know of are: corrupted .htaccess file and PHP memory limit.

1. Checking for Corrupt .htaccess File

The very first thing to  do when  you want to solve the internal server error in WordPress is  to check for the corrupted .htaccess file.

You can do so by renaming your main .htaccess file to something like .htaccess_old. To rename the .htaccess file, you have to login to your site using FTP or File Manager app in your hosting account’s cPanel dashboard.

Once you connected, the .htaccess file will be located in the same directory where you will see folders like wp-content, wp-admin, and wp-includes respectively. 

Once you have renamed the .htaccess file, try visiting your site to see if this solved the problem. If it did, then congrats to you but before you move on with other things, make sure that you go to Settings » Permalinks page in WordPress admin area and click the save button without making any changes.A new .htaccess file will be generated for you with proper rewrite rules to ensure that your post pages do not return a 404 error.

If checking for the corrupt .htaccess file solution did not work for you, then you need to continue reading this article.

2. Increasing the PHP Memory Limit

500 internal server error can also occur if you are exhausting your PHP memory limit.
If you are seeing the internal server error only when you try to login to your WordPress admin or uploading an image in your wp-admin, then you should increase the memory limit by following these steps:

• Create a blank text file called php.ini
• Paste this code in there: memory=64MB

• Save the file
• Upload it into your /wp-admin/ folder using FTP

If increasing the memory limit fixed the problem for you, then you have only fixed the problem temporarily. You still need to find the cause that is exhausting your memory limit.

This could be a poorly coded plugin or even a theme function. 

We recommend that you ask your WordPress web hosting company to look into the server logs to help you find the exact diagnostics.

If increasing the PHP memory limit did not fix the issue for you, then read other guidelines below. 

3. Deactivate all Plugins

Simply go to the WordPress admin area and click on ‘Plugins’. Now you need to reactivate one plugin at a time until you find the one that caused the issue. Get rid of that plugin, and report the error to the plugin author.

Most likely the error can be caused by a specific plugin. It is also possible that it is a combination of plugins that are not playing well with each other. If disabling all plugins fixed the error, then you know it is one of the plugins that is causing the error.

4. Re-uploading Core Files

If the plugin option didn’t fix the internal server error, then it is worth re-uploading the wp-admin and wp-includes folder from a fresh WordPress install.

NOTE: This will NOT remove any of your information, but it may solve the problem in case any file was corrupted.

Your FTP client will  transfer those folder to your server. It will ask you whether you would like to overwrite the files. Select ‘Overwrite’ and then select ‘Always use this action’.

If all methods doesn't work for you to fix internal server error on your website, then contact your web hosting support team so they will be able to check the server logs and locate the root cause of the error.